The invention relates to improvements in continuous plastic releasably interconnecting fastener strips of the type with zippers or matched shaped profiles on the surfaces adapted to be mounted on the upper edges of a bag or on a similar structure.
The invention particularly contemplates the provision of an improved closure construction for use with thin flexible film bags as are utilized for packaging merchandise marketed in stores. The bags are frequently manufactured separately, and the bag supplier brings in the flexible from another source and attaches them to the bags either prior to filling or at the time of filling. The flexible reclosable fasteners commonly come in strips which are continuous, and for convenience of handling are supplied in roll form so that they are unrolled and cut at the time of being attached to the bags. The bags will be used to contain a wide variety of materials from foodstuffs to hardware, and the materials will come in any form from liquid to fine granulated material or more large objects. The fastener strips to be satisfactory, must be easily handled and easily attached to the bags and must accommmodate the contents of the bag, that is, they must be able to close and seal the bags while remaining operative themselves so as to be reopenable and reclosable. In certain types of contents, it is essential to provide a fastener which will seal the interior of the bag and prevent inadvertent or unintentional opening before use. Different developments have been attempted to accomplish this purpose, such as by providing plastic elements which temporarily hold the fastener profiles together or actually sealing the separating openings flanges of the profiles together until such time as the bag is used. Each of these constructions have presented some difficulties, and frequently are not suited to all types of bag contents.
Another problem which has faced the art is the provision of a satisfactory pair of fastener strips which can be easily and conveniently handled at the time of manufacture and rolled up and stored until use. One way this is done is by first interlocking the fasteners and then rolling the strips into a roll with the strips being unrolled at time that they are attached to the bag top. In certain instances these strips have to be separated before being sealed to the bag edges, and accordingly it would be desirable to be able to spool them in this fashion, but nevertheless to be able to keep them linked together so as to prevent interwining and insure correct positioning on the reel.
It is accordingly an object of the present invention to provide an improved fastener strip construction which avoids the difficulties of constructions heretofore available in the prior art and which can be particularly easily attached to the top edges of a bag.
A further object of the invention is to provide an improved fastener strip construction wherein the strips can be handled and shipped with the profiles unlocked and separated from each other so that they do not have to be separated at the time of attachment to the bag and wherein they are still maintained in their oriented relationship for handling and attachment to the bag top.
A still further object of the invention is to provide an improved fastener strip construction wherein an interconnecting web is utilized constructed and attached so that it aids in the handling of the strips and their attachment to the bag tops, provides a sealed bag after the strips have been attached to the bag, and protects the small critically shaped profiles during attachment to the bag and from the contents after the strips are attached to the bag, and the bag has been filled. The web is so shaped and so sized so that the strips will function in an improved manner with the bag, and the profiles are continued to be protected from the bag contents after use and during the times the bag is emptied and refilled. An improved bag construction results in that a bag is provided which cannot be accidentally opened or spilled and wherein the film web acts as a safety valve permitting expansion of the bag contents and distortion of the bag sides without creating the previous risks of accidentally separating the profiles with consequent spilling of the contents or contamination thereof from foreign material.
Other objects, advantages and features, as well as equivalent structures which are intended to be covered herein, will become more apparent with the teaching of the principles of the invention in connection with the disclosure of the preferred embodiment thereof in the specification, claims and drawings, in which: